Wg. Ambrose et Pe. Renaud, BENTHIC RESPONSE TO WATER COLUMN PRODUCTIVITY PATTERNS - EVIDENCE FORBENTHIC-PELAGIC COUPLING IN THE NORTHEAST WATER POLYNYA, J GEO RES-O, 100(C3), 1995, pp. 4411-4421
Polynyas, recurring ice-free areas amid pack or drift ice, are model s
ystems for predicting the potential productivity of pelagic and benthi
c communities in polar regions. The Northeast Water Polynya on the nor
theast Greenland continental shelf and surrounding ice-covered areas w
ere investigated to address the influence of water column processes on
the benthos. We measured infaunal density, polychaete biomass, sedime
nt carbon concentration, and benthic pigment concentration from replic
ate box cores at 16 stations. Benthic pigment concentration is the mos
t important predictor of infaunal density and polychaete biomass, expl
aining nearly half of the variance in these variables. Benthic pigment
concentrations are strongly related to the concentrations of water co
lumn pigments, suggesting that the signal of water column productivity
is received on the bottom and. transmitted to the fauna. The highest
densities and biomass are found near the mouth of the Northern Trough
and are probably fueled by biogenic material produced by the developin
g phytoplankton community as it: is advected down the trough. Density
and biomass are also generally higher under the ice-free water of the
Northern Trough than under the ice-covered Southern Trough. This patte
rn may be explained by greater primary productivity in the Northern th
an Southern Trough and/or by a decoupling of water column and benthic
process by zooplankton grazing in the south. Sediment organic carbon c
oncentration is between 0.5% and 1.5%, indicating that the sediment is
probably not an unusually large carbon sink relative tb shelf and dee
p-sea systems in temperate and polar regions. These results reinforce
an emerging pattern of efficient transfer of carbon from water column
to benthos in high latitudes. Owing to the abundance of small-scale an
d mesoscale areas of enhanced phytoplankton production in the Arctic (
e.g., leads, marginal ice zones), benthic biomass in the Arctic Ocean
and surrounding seas may be higher than previously anticipated.